Southern slider

Lerista is a large Australian genus of burrowing skinks, often called sliders or fine-lined sliders, and it is a gift to evolutionary biologists. Within this one group are species with five toes on every foot, species with tiny two-toed or one-toed limbs, and species with no external limbs at all.

A 2008 study by Adam Skinner, Michael Lee and Mark Hutchinson concluded that toes and limbs have been reduced many separate times within Lerista, sometimes within less than 3.6 million years. That makes it one of the best natural experiments anywhere for understanding how lizards become snake-like.